Bill, i am still amazed at this happening. Aside from the obvious bummer, i think this could be used as a great learning tool, and one hell of a display piece
Burt Foster has some superglue that might help you out
Did you temper before cryo? If you did not then that is your culprit. Another is that your oil is a bit fast leading to increased stresses. If you heat your oil prior to quenching try leaving it cold(room temp) next time.
Thanks Del, I did not temper before cryo but I never have in the past and I am using texaco type a which is a pretty slow oil. Basically the only thing that I did different from what I have done for the last ten years that I have been doing this is to go into the LN2 as soon as the blade reached room temp instead of waiting my normal 24 hours with the blade in the freezer. I did it this way because it is supposed to enhance finer carbide precipitation in the grain boundaries.